Panera is facing a lawsuit after a grilled cheese was found to have a “secret” ingredient.

Elissa and John Russo’s 6-year-old daughter was diagnosed with a peanut allergy when she was around 18-months-old. Ever since, both parents have been alert and attentive to her allergy, informing all restaurants and other establishments of the allergy and also carrying “epi-pens” with them at all times.

Late January, Elissa Russo ordered her daughter a grilled cheese sandwich through Panera’s online ordering service. Russo made sure to specify in two different places that the grilled cheese order was for her daughter who has a peanut allergy.

However, 2 teaspoons of peanut butter were placed onto the grilled cheese during its preparation.

Unfortunately, the peanut butter was not discovered until Russo’s daughter bit into the sandwich. The girl did not immediately show symptoms, but was rushed to the hospital and kept overnight.

According to the Boston Globe, a Natick Panera manager blamed the incident on a “language” issue, suggesting a worker with limited English saw the allergy specifications and misconstrued them to be an addition to the sandwich, rather than a warning. The Russo family finds the excuse completely unfathomable.

The family followed through with a lawsuit recently, asserting that the restaurant “engag[ed] in unfair and deceptive business practices by adding peanut butter to the plaintiff’s grilled cheese sandwich knowing that [she] has a life-threatening peanut allergy.” Panera’s website states that its locations cannot guarantee items are allergen-free because of the shared equipment. Although, the Russo family’s attorney believes this is not an incident of accidental contamination.